Steering columns in motor vehicles are known, in which a supporting unit which is connectable to the chassis of the motor vehicle, for example in the form of bracket parts, is provided, and a displacement unit which is held on the supporting unit and comprises, for example, a steering column tube, is provided, wherein a steering spindle is mounted rotatably in the displacement unit. The displacement unit is arranged here displaceably in relation to the supporting unit in order to provide flexibility of the steering wheel in the event of a crash by means of a corresponding displacement of the displacement unit in relation to the supporting unit connected to the chassis, in order to improve the crash behavior. When the displacement unit is displaced in relation to the supporting unit, an energy absorption device which comprises an energy absorption element absorbs crash energy, wherein different configurations are known here via which crash energy can be absorbed in a controlled manner over the displacement path of the displacement unit in relation to the supporting unit.
For example, DE 10 2005 052 123 B3 discloses a steering column in which an energy absorption part is provided between the supporting unit and the displacement unit, said energy absorption part being secured on the displacement unit and comprising an elongated hole. A bolt which is secured on a rail and comprises widened portions and which, during normal operation, is secured on the supporting unit via a fixing element is guided in the elongated hole. In the event of a crash, the bolt can thus move in the elongated hole, wherein, because of the widened portions of the bolt, the energy absorption part, and in particular the elongated hole of the energy absorption part, is deformed in such a manner that a controlled absorption of energy over the displacement path is achieved.
DE 10 2008 034 807 B3 pursues an alternative concept, wherein a displacement unit is likewise arranged here displaceably in relation to a supporting unit, wherein the displacement unit and the supporting unit are not displaced in relation to each other during normal operation, but a displacement of the displacement unit in relation to the supporting unit is provided in the event of a crash in order to absorb energy. A bending strip is provided between an engagement part, which is secured on the supporting unit during normal operation, and a rail, which is secured on the displacement unit, which bending strip is configured in such a manner that, in the event of a crash, it absorbs energy in a defined manner by means of its deformation during a displacement of the displacement unit in relation to the supporting unit.
Via the energy absorption mechanisms, i.e., for example, the deformation of the elongated hole of the energy absorption part or the deformation of the bending wire or bending strip, a predefined force-travel behavior can be correspondingly predefined for the absorption of the crash energy over the displacement path in the event of a crash since the relative displacement between the supporting unit and the displacement unit can always be the same and is not changed by the longitudinal adjustment of the steering column.
The energy absorption mechanisms described require, for their construction, in each case at least three parts in the form of an engagement part, a rail and the bolt or the bending strip.
DE 10 2007 002 091 A1 discloses a steering column with a crash device, in which a bead is provided as the crash device, which bead is deformed by the displacement of the guide box during the crash.
As energy absorption elements, different geometrical configurations, for example bending tabs, bending wires, bending tear tabs and crash beads, are known from the prior art. For each adaptation of the energy absorption level to a type of vehicle, the energy absorption elements known from the prior art have to be adapted in each case with regard to their geometry and/or with regard to their material and the material strength. This accordingly requires investments in new tools and in the corresponding tests for each energy absorption element adapted in this manner.